Multimodal Composite Iron Oxide Nanoparticles for Biomedical Applications

Abstract

Background: Iron oxide nanoparticles (IONPs) are excellent candidates for biomedical imaging because of unique characteristics like enhanced colloidal stability and excellent in vivo biocompatibility. Over the last decade, material scientists have developed IONPs with better imaging and enhanced optical absorbance properties by tuning their sizes, shape, phases, and surface characterizations. Since IONPs could be detected with magnetic resonance imaging, various attempts have been made to combine other imaging modalities, thereby creating a high-resolution imaging platform. Composite IONPs (CIONPs) comprising IONP cores with polymeric or inorganic coatings have recently been documented as a promising modality for therapeutic applications.

Methods: In this review, we provide an overview of the recent advances in CIONPs for multimodal imaging and focus on the therapeutic applications of CIONPs.

Result: CIONPs with phototherapeutics, IONP-based nanoparticles are used for theranostic application via imaging guided photothermal therapy.

Conclusion: CIONP-based nanoparticles are known for theranostic application, longstanding effects of composite NPs in in vivo systems should also be studied. Once such issues are fixed, multifunctional CIONP-based applications can be extended for theranostics of diverse medical diseases in the future.

Keywords: Iron oxide nanoparticles; Magnetic resonance imaging; Optical imaging; Photoacoustic imaging; Ultrasound imaging.

Fig. 1

Schematic illustration of biomedical application of IONPs

Fig. 2

A Diagrammatic representation of synthesis process, B TEM images of core–shell Fe₃O₄/TaOx NPs. CIn vivo CT images and D rat MR images of NPs pre and post injected rat. Reference [59], reprinted from American Chemical Society 2012 Copyright

Fig. 3

Diagrammatic representation of A double emulsion water–oil-water method leads broad size MCs distribution. B Microporous membrane uniform nanoparticle synthesis through a PME method, C PEG modified Vesical Fe₃O₄@PEG–PLGA MCs comprising a cavity, an Fe₃O₄ rooted PLGA shell. D US in vivo images enhanced mouse liver US contrast, e nude mice in vivo MR images. Reference [67], reprinted from American Chemical Society 2015 copyright

Fig. 4

A Diagrammatic representation of the ⁶⁹Ge ion doped iron oxide nanoparticles. B PET in vivo images and c mice images with MR T₂-contrast before and after administration of ⁶⁹Ge-doped NPs intravenously. Reference [81], reprinted from Wiley-VCH 2014 Copyright with permission

Fig. 5

A Diagrammatic representation of core–shell NaYF₄:Yb³⁺, Tm³⁺@FexOy nanocrystals synthesis process. B Up-conversion nanocrystals of in vivo luminescence imaging after the systemic administration. C Armpit region MR images after the administration of the NPs. Reference [88], reprinted from Elsevier 2011 Copyright with permission